Hacker News Reader

"Do not perform table alter commands. Table alter commands introduce locks and downtimes. Instead, use live migrations."

You know what avoids alter? Going schemaless.

Or using a more appropriate RDBMS that allows for online and transactional ALTER commands?

But schemaless does not help migrating the data from structure A to structure B.

Consider, that in this case, the json text field is schemaless. How is that different from other schemaless databases?

If anything, you should state that if you wanna avoid alters, use CQRS, not just shcemaless